The Δp25 mutant in A. nidulans does not exhibit a nud phenotype. (A) Protein sequence alignment of p25 proteins from A. nidulans (A.n.p25), N. crassa (N.c.p25; Lee et al., 2001), and mouse (Eckley et al., 1999). Identical amino acids are boxed in black. Blue lines indicate Hexapeptide repeats in A. nidulans p25 identified using the Simple Modular Architecture Research Tool (SMART) program. (B) The Δp25 mutant grows slightly more slowly than the wild type on plates but is much healthier than a typical nud mutant such as ΔnudA (dynein heavy chain or HC) or ΔArp11. (C) Unlike the ΔnudA and ΔArp11 mutants, the Δp25 mutant exhibits normal nuclear distribution. The strains were grown in liquid Y + UU medium for 7.5 h at 37°C before being fixed and stained with DAPI for visualizing the nuclei. Bars, 5 µm. (D) A quantitative analysis of nuclear distribution in the Δ25 mutant in comparison to that in a wild-type control strain. More than 200 germ tubes were analyzed for each strain. Means and standard deviations (error bars) were calculated from three experiments. No significant differences are revealed at the P-value of 0.05.